Arch.



D. B.ALUTEN.

ARCH.

APPLICATION FILED MAR. 2,1908.

1,186,108, PatentedJune6,1916.

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ARCH.

APPLlCATlON FILED MM. 2. 190a.

Patented June 6, 1916.

Wfwesses:

UNITED STATES PATENT OFFICE.

DANIEL B. LUTEN, OF INDIANAPOLIS. INDIANA.

Anon.

Specification of Letterslatent.

Patented June 6, 1916.

Original application filed May 17, 1902, Serial No. 107,812. Divided and this application filed March 2,

1908. Serial No. 418,793.

To all whom it may concern:

Be it known that I, DANIEL B. LUTEN, .a citizen of the United States, residing at Indianapolis, in the State of Indiana, have invented new and useful Improvements in Arches, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to improvements in concrete construction particularly of arches and especially when reinforced with embedded tension members to reduce the material otherwise required to transmit thrusts and loads from the structures to their foundations.

This application is a division of an application filed by me May 17, 1902, Serial This invention is illustrated in the accompanying drawings forming part of this specification, in which the same reference characters designate like parts throughout the several views, and in which ;-Figures 1 and 2 are quarter plan views of an. arch showing novel arrangements of the footings. Fig. 3 is a half elevationand half longitudinal section of an arch of constricted waterway. Fig. 4 is a transverse section taken on the center line of Fig. 2. Figs. 5 and 6 are views similar to Figs. 3

and 4 for an arch in which the waterway is constricted by a general curving of the in-- ner surface of the arch. Fig. 7 is an elevation and part section of an arch in which the transverse curvature of the inner surface varies with different points .in the span. Fig. 8 represents half-sections transverse to Fig. 7 at the centerand near the abutment, and illustrating the different curvatures. Fig. 9 is a transverse section of a reinforced concrete arch bonded longitudinally and transversely by embedded tension members and having its thrust resisted by tension members from abutment to abutment across the bed of the stream.

' In arches which are to support heavy embankments of earth and which should be designed to secure the maximum discharge of water, economy of material is secured by thickening the arch rib and the abutments toward the middle of the embankment where the load is heaviest. This strengthening has hitherto been accomplished by adding material on the outside, the intrados remaining straight or cylindrical. In my arch however I prefer to add the increased thickness to the inside, which causes the ends to flare outwardly to form a conical or funnel-shaped intrados and by which arrangement is secured both maximum discharge and increased strength.

Figs. 1 and 2 show arches of the horseshoe or warped end type, in which 50 indicates the barrel or rib of the arch, 51 the warped end, 52 the abutment in plan, and 53 the inner bounding line of the abutment, straight in Fig. 1 as part of the conical inner surface, and curved in Fig. 2 as part of a double curved surface composing the intrados. The effect of great discharge is more fully realized in the form of walls or abutments shown in Fig. 2 inwhich the inner' wall 53 may be curved on a true cycloidal curve whereby the barrel of the arch forms a Venturi tube capable of discharging considerably more water than the old form of arch.

Figs. 3 and 4 show an arch of the wing and spandrel type with the inner surface of the funnel or conical form at the ends as shown at 54 whereby from 25 to 50 per cent. greater discharge is secured. The same amount of material is used as in the straightbarrel ordinarily used, indicated by dotted lines in Fig. 4, and the arch is of the same strength. 55 is the spandrel and 56 the wing at the end of the arch to retain the embankment or filling 57. The section of the abutment 52 is shown at the right in Fig. 3, the same being taken at the transverse center of the arch.

In Figs. 5 and 6,the arch 50 has the elliptical form, with the warped end 51, the side walls 53, and its inner surface curved at the ends in the form of a cycloid 1 whereby a structure especially adapted for a heavy loading and maximum discharge is secured.

The arch of Figs. 7 and 8 is designed for 100 locations where there is deep water and. low banks, such as a deep stream or millrace, and where at the same time a good appearance is desired. For the sake of appearance, an

arch should have its springing above the 105 nel-shaped intrados, the-face of the arch 110 in section at the right of Fig. 7, and being may be made to present the proper appearance by designing it flat with springings above the water line while the main body of the arch which sustains the principal part of the'loading may have its springing near the base of the abutment, which accompanied by the considerable rise that results, produces a very strong and economical structure. In such an arch the inner surface may be made straight transversely at the crown, and sagged at the haunches and straight again at the springing, or the conical form may be given in varying degrees to different parts of the inner surface. This funnelshaped device has the additional function of increasing the discharge capacity of the arch. Thus, it is a well-known fact that a Venturi tube or funnel-shaped discharge f pipe will discharge under slight head a much greater quantity of water than a straight tube. In these figures therefore, 57 indicates the roadway filling, and 58 the limits of the en'il'ianlnnent. The spandrel walls are straight and the transverse center of the arch as shown by the line 59 has its springing point 60 considerably below the Water line (31, the abutment 52 in this portion of the arch, being of the form shown designed for strength and stability. At the ends of the abutment however the abutment is made high with the inner and outer walls 53 and 62 extended about to the water line. The arch ring 50 then springs from the top of this abutment and thus the structure has the appearance of a handsome elliptical arch with springing lines at the water line. In transverse section as shown in Fig. 8, the curve from the center 59 to the edge 63 on the left is gradual and substantially of the Venturi form, but nearer the sides as shown enlarged at the right in the said figure, the flaring is greater. so that the curve for maxi mum discharge is somewhat departed from. The net result for the whole structure is that an arch is obtained having a neat and handsome external appearance, that is much stronger than one would be if designed on the lines of the external arch ring, if indeed one could be so constructed at all, and one that is capable of greater discharge than the straight-barrel arch of either type.

In I-ig. 9, one side of the arch is shown Copies 02 this patent may be obtained for with the usual spandrel end. 55 and the other side with the warped end 51. The inner surface is formed to a cycloidal 64- at the up-stream side and to a conical surface 65 at the down-stream. side. The springing point 60-is above the water line 61 at the spandrel end, and the springing lines are vertically curved. Longitudinal reinforcing members 66 are embedded in the arch rib and transverse reinforcing members 67 bond the arch transversely, andalso act as stirrups to restrain the longitudinal members 66. The abutments are tied together by longitudinal ties G S, embedded in a thin concrete pavemenfg- 69, to render the bridge proof against undermining in floods, and this pavement is provided with aprons at up-stream and down-stream sides shown at 71. In a doubly curved arch of this form, and thus re inforced, any distortion of the arch ring would be resisted to a much greater degree than in the straight cylindrical arch for the same reason that a buckle plate is stronger than a flat sh et under transverse forces. The distance of most of the material from the general neutral axis of the structure has been much increased. and the radius of gyration of the section is greater than that of a cylindrical arch.

line while the invention has been described specifically with reference to particular details of construction, it is to be understood that it is not so limited, but on the contrary may be embodied in various forms without departing from the scope or principle of the same.

Having thus described my invention, what I claim and desire to secure by Letters'Patent is:

An arch having an inner surface convex in transverse section, the degree of convexity increasing from the middle of the span toward the end of the span, and the springings of the arch being highest at the faces of the arch.

In witness whereof, I have hereunto subscribed my name in the presence of two witnesses.

DANIEL B. LUTEN.

Vtlitnesses J. I Coon, C. H. KNI HT.

five cents each, by addressing the Commissioner of Patents, Washington, D. G." 

